1. Field of the Invention
The present invention relates to a rake arm assembly with torsion spring support for a finger wheel, constituting an improvement over existing rake arm assemblies.
2. Brief Description of the Prior Art
A finger wheel rake employs a plurality of rotating tined wheels supported on a frame which is towed sideways across a field of cut forage to form windrows. As the frame is moved forward, the finger wheels are skidded across the ground and caused to rotate. The industry-standard finger wheel weighs about 54 pounds including the finger wheel spindle and hub and makes three-finger contact with the ground. While it is important that the rake apply some ground pressure for effective raking, it is also important that some of the weight be taken off the finger wheel. Too much weight on the finger wheel will cause the fingers to bend as the wheel is dragged into a mound such as a gopher hole, rock or the like. When the fingers are bent more than an inch or two out of vertical, raking action is compromised and the finger wheel must be replaced or repaired.
The industry standard rake arm assembly consists of a rake arm pivoted from a support frame. A finger wheel is mounted on the end of the rake arm at an angle to the frame. An upstanding lever is welded to the rake arm adjacent the finger wheel spindle and a pipe mounted on the frame. An extension spring is strung between the lever and the pipe with a chain passing through its core to prevent over extension. The chain also provides a means for raising the finger wheels for transport when the pipe is reciprocated on the frame.
In a downward direction, the rake arm assembly allows the finger wheels to follow the contours of the ground, the extension spring support, however, maxing out at about six inches below the starting position, at which point the finger wheels apply little or no pressure on the ground. In an upward direction, the extension spring provides no support and the full weight of the finger wheel is on three fingers. Hence, over a range of about 6 inches, the ground pressure applied by the finger wheels varies all the way from 0 to 54 pounds.
With a typical rake arm assembly, after the finger wheels are raised, the operator must get off his tractor and set a pin in the pipe to secure the unit in raised position, the reverse operation being required when he wants to lower the finger wheels. Most farmers do not like to get off their tractors as time is money. In addition, not infrequently the chain links tangle as the finger wheels are raised. This causes the finger wheels to be held in partially raised position when they are lowered, requiring the operator to dismount and straighten out the tangle before starting raking.